Ann: Major New Zinc Lead Anomalies at Oposure, page-7

Thanks for your kind remarks in a previous post.

It does take a lot of work to produce some of my posts but with a life long interest in this style of exploration it is 'fun' for me and intersects with investment/speculation. Some of the challenges to present visual data have recently led me to begin learning aspects of gimp/photoshop to combine and scale images as shown below.

For me AZS, in particular, brings back pleasant memories of working in Mexico in the 70's. While I worked further south the local prospectors took us out to inspect prospects with mineralised outcrops, mine dumps, pits, underground workings etc all over the place and such high grade samples as reported by AZS were not uncommon. The operative word is grab sample where your eye hits on the "shiny/colourful" high grade material and the drab material which represents the bulk of the dump doesn't get assayed.

While such samples are not representative they definitely attract attention and further work is needed to see if they are significant.

Prior to the 1910 Mexican revolution there was a very rich history of mining going back centuries. Post that until the 1970s the scale of exploration was apparently relatively limited and this left places like Mina Blanca sitting as "forgotten" deposits some of which were held by folks who just let them sit in the ground for whatever reason. E.g. Sara Alicia.
I suspect there has been some change in Mining Laws since the 1970's when the company I worked for were required to have a 51% Mexican partner something AZS do not appear to be dealing with. Such Law changes can open or close jurisdictions to exploration.

"MINA BLANCA" GEOCHEM SURVEY.
The company gave these details about the survey:

This is a fairly rugged area to be doing soil sampling as shown in google earth images below. At face value "soil samples" are treated as being the same across the survey - probably not true but perhaps close enough given the relatively steep topography where scree/subcrop/outcrop are probably dominant. IMO there are unlikely to be any well developed soil profiles as would be expected in areas of less topo relief. As such the Zn to 3% levels may in fact represent near bedrock values albeit on 50x100m spaced sampling.

PXrF - qualitative vs quantitative? again shouldn't be a major issue if the instruments are calibrated properly. Elements like Zn and Pb are quite reasonable with PXrF but some others (Co? in particular) are not. They have taken sieved samples so further geochem can be done if warranted. PXrF gives 35 elements to a reasonable level at a fraction of the cost and time involved with lab assays.


GEOCHEM GEOLOGY AND TOPOGRAPHY
I was interested in how the Zn Pb geochem related to geology and topography.
From the September 17 2017 presentation there is this composite plan/section showing a model for the Mina Blanca down thrown section:


By merging the geochem Zn data with these you get (approximate only):

Perhaps of more interest is the section line X-Y which shows why AZS are quite excited by the circled area on the geochem. Perhaps not a great surprise as the out crop was already known....
The Zn (Pb/Mn/Cu)anomalies along the X-Y line coincide with outcropping Arenillas formation altered limestones and provide some proof of concept for the model.


GEOCHEM AND TOPOGRAPHY
I have made a crude attempt to drape the Zn Geochem over google earth images.

Vertical images.
Zn Geochem overlain by topo

Zn Geochem transferred to topo



Tilted views of the Mina Blanca geochem area with manual transfer of Zn geochem anomalies. Pb anomalies will give a similar result as could Mn Cu and others.
Topo google earth

Topo with annotations. Yellow lines to highlight topography. Zn anomalies in Red.


This combination of topography and the Zn geochem anomalies IMO suggests some stratigraphic control which proposed further exploration will better define economic potential. The purple line could represent an approximation of the surface trace of mineralised Arenillas Formation especially in the big valley near the main anomaly and possibly to the north over the crest of the ridge.
Good outcrop to the south may preclude extensions of this unit in that direction but there are some Zn anomalies that need explanation.

Mina Blanca itself does not appear to have a significant Zn component as its location is topographically below an area of raised Zn in soils.

FORWARD PROGRAM AT OPASURA
As of this announcement the resource drill out has not been completed:

When the Oposura resource drill-out has been completed, the Company’s focus will shift to an expansionary phase to test for repetitions and extensions of the high-grade Oposura massive sulphide deposit, and to explore for new styles of mineralisation like identified at Mina Blanca.

How much exploration is warranted here? IMO it should be fairly limited so that relatively scarce financial resources are left for Opasura and Sara Alicia. For AZS there needs to be a shift from Explorers to Miners if they are to meet their stated goal for Opasura. I found this post by Scarpa on another company to be potentially relevant.

Weekend musings and play for me and general consumption. DYOR
Gltah